The correct answer among the choices listed is the second option. The scientific notation of 6,370 kilometers is 6.370 × 10^3 kilometers. It is by this way that scientists are able to handle very large or small numbers. They just move the decimal point and multiply it by 10 raise to the power of n where n is the number of times the decimal point is moved. If to the left, then n is positive. If to the right, then n is negative.
